A wide variety of printing ribbons having a printing portion and a correction portion have been disclosed in the prior art. For example, see U.S. Pat. Nos. 3,143,200; 3,273,686 and British Pat. No. 961,108. Commercial embodiments of such ribbons are similar to the ribbons in said U.S. patents and involve a backing layer extending across the full width of the ribbon to prevent the printing portion from being contacted directly by type face. Further, such prior art ribbons are characterized by the correction portion of the ribbon being of greater thickness than the printing portion.
Composite ribbons of the type having a backing extending across the full width of the ribbon and wherein the correction portion is thicker than the remainder of the ribbon have an objection to their use in certain circumstances. Thus, recent design changes in some typewriters precludes use of such ribbons due to the fact that they are too thick and cannot pass through the guides of the typewriters. The ribbon of the present invention is structurally interrelated in a manner so that the ribbon may be used on any typewriter while at the same time will enable a longer length of the ribbon to be wound on a standard spool than was possible with the ribbons disclosed in the prior art such as the ribbon in U.S. Pat. No. 3,273,686.
The printing ribbon of the present invention includes a longitudinally extending printing portion of inked fabric and a longitudinally extending correction portion joined thereto. Each portion is about the same width, and constitutes approximately one half the width of the ribbon. The printing ribbon is comprised of a single thickness of fabric which is the thickest portion of the ribbon and has a thickness of not more than 0.0035 inches.
The correction portion of the ribbon includes a backing which carries a layer of correction material thereon. The width of the layer of correction material is narrower than the width of the backing. The side edges of the correction material are parallel to but spaced inwardly from the side edges of the backing. One side edge of the backing is welded to a side edge of the printing portion of the ribbon.
The correcting portion of the ribbon lies in the same plane as the printing portion and preferably is slightly thinner than the printing portion of the ribbon. The side edge of the correction material adjacent the center of the ribbon is spaced from the adjacent side edge of the printing portion by a gap. The other side edge of the correction material is spaced from the adjacent edge of the backing by a gap.
It is an object of the present invention to provide a printing ribbon for a machine such as a typewriter and which is capable of being utilized in all makes of typewriters.
It is another object of the present invention to provide a printing ribbon having a printing portion and a correction portion wherein the printing portion is a single thickness of fabric having a thickness greater than the thickness of the correction portion and less than about 0.0035 inches.
It is another object of the present invention to provide a printing ribbon having a printing portion and a correction portion constructed in a manner so as to enable larger amounts of the ribbon to be wound on a conventional spool.
It is another object of the present invention to provide a printing ribbon having a printing portion spaced from a correction material by a gap to preclude bleeding of ink into the correction material.
Other objects will appear hereinafter.